JPS60172424A - Fire extinguishing device for electric discharge machine - Google Patents

Abstract

PURPOSE:To stop operation of an electro-discharge machine with a detection signal out of a fire detector, by installing a pressure switch, operating in conjunction with internal pressure in a fire extinguisher, and a circuit linking a power source with the electro-discharge machine via the pressure switch, in the said machine. CONSTITUTION:When a fire extinguisher 1 is filled up with an extinguisher agent in a state of being specified, pressure inside the fire extinguisher goes up to some extent. When air pressure inside the fire extinguisher drops, a variation in the pressure is utilized, and a pressure switch 1a, releasing a switch for a main line of a power source for an electro-discharge machine, is installed. A fire detector 3 has several types of detecting elements, for example, 3a is for smoke, 3b for gas, 3c for infrared rays and 3d for temperature like that - thus each of quantities, values and content thickness are detected in this way. In a discriminator circuit for these detecting elements, when any one operates for detection and enters a warning range prior to a fire, a switch 2 of a working voltage pulse feed circuit 6 is turned off, and the electro-discharge machine is once stopped, and when there is no fear for anything as other detecting elements do not operate, the switch 2 is made to be turned on again.

Description

[Detailed description of the invention] The present invention relates to a fire extinguishing device for an electrical discharge machine.

Wire-cut electrical discharge machines use water via ion-exchange resin, so there is no need to think much about fire extinguishing equipment, but conventional electrical discharge machines that use mineral oil such as kerosene as the machining fluid can prevent fires. The danger of fire cannot be avoided, and a fire extinguishing device is required to extinguish the fire. This invention is equipped with a fire extinguisher that injects extinguishing agent from a high-pressure storage container, and when a fire occurs, the extinguishing agent squirts out and extinguishes the fire, and at the same time, a pressure switch is activated by utilizing pressure fluctuations inside the extinguisher. It was designed to open. In addition, in order to prevent a fire extinguisher that uses extinguishing agent from operating when the detector is activated even though there is no actual fire, or because the detector malfunctions, a warning area is set before extinguishing. I set something up. It uses a discrimination circuit that operates by separately detecting physical phenomena such as smoke, gas, infrared rays, and temperature, and comparing the detected conditions with pre-prepared standards of detected values and detected conditions in the event of a fire. If there is no fire, the switch of the pulse supply circuit, which is a part of the circuit of the electric discharge machine, is opened, and machining is stopped once, so that detection by another detector is not added within a predetermined time, and the fire is detected. If there is no concern about this, the switch can be turned on again immediately to continue machining.

- When the detection state detected by the force detector is determined by the discrimination circuit to be a fire, a signal is immediately sent to the fire extinguisher drive device that operates the fire extinguisher to activate the fire extinguisher and spray out the extinguishing agent. As the pressure inside the fire extinguisher changes as this extinguishing agent squirts out, the pressure switch connected to the fire extinguisher opens the switch and cuts off the power supply to the electrical discharge machine. It was made by sea urchin.

Next, the fire extinguishing system of the present invention will be explained with reference to the illustrated drawings.

1 is a fire extinguisher, and when this fire extinguisher 1 is filled with extinguishing agent to a predetermined state, the pressure inside rises, and when a fire occurs, the extinguisher is activated and the extinguishing agent spouts out, extinguishing the fire. If the pressure inside the extinguisher decreases, or if some of the extinguishing agent leaks out after not being used for a long time, or if the extinguishing agent deteriorates and the air pressure inside the extinguisher decreases, the electrical discharge machine A pressure switch 1a is provided to release the round wire switch of the power source. The switch 1a shown in the figure is a switch that opens and closes with a bellows that expands and contracts with the internal pressure of the fire extinguisher 1.

In addition, it should be noted that the structure is such that a part or all of the power line fuse attached to it is destroyed by the ejecting action of the extinguishing agent, or that the membrane is below the predetermined value of the filling pressure of the extinguishing agent in the fire extinguisher. It may be possible to make it possible to blow out the fuse together with the power line fuse when the voltage drops, so that it can be used to check both the power line fuse and the fire extinguisher. 2 is a switch for the processing voltage pulse supply circuit 6, and 3 is a fire detector that uses physical or chemical changes in the environment when a fire occurs or enters a warning area. For example, 3a is a detector for detecting smoke, 3b is a gas, 3C is an infrared ray, and 3d is a detector for detecting the temperature, etc., respectively. Reference numeral 5 is a discrimination circuit for these detection elements, and the third circuit is installed in the switch 2. By turning off the switch, only the electrical discharge machining is temporarily stopped, and after waiting for a while, if the sensor element does not detect anything and there is nothing to worry about, turn on the switch 2 again. do. For example, a self-resetting device such as a timer or an AND circuit may be provided to detect physical phenomena of the plurality of detection elements 3a to 3e of the fire detector 3, that is, light, temperature, infrared rays, and gas. When all or a predetermined combination ignites, the fire extinguisher 1 is activated by the signal from the discrimination circuit 5, and the pressure inside the extinguisher 1 decreases as the extinguishing agent is jetted out, the pressure switch 1a is activated and the electrical discharge machining starts. Open the power supply that supplies power to the machine and then turn off the power.

As described above, in this invention, when a fire occurs during electrical discharge machining, when the fire extinguisher starts ejecting as detected by the detector, the pressure switch is opened due to the accompanying change in the internal pressure of the fire extinguisher, and the electrical discharge machine is activated. 5. Warning areas should be set in advance before a fire to prevent extinguishing agent from spewing out when electricity is turned on. In this area, instead of turning off the power supply to all parts of the electric discharge machine by detecting it from the physical phenomenon in the electric discharge machining atmosphere, we turn off only the switch of the machining voltage pulse supply circuit and observe the situation for a while. If other detection elements do not operate and there is no fire, the machining voltage pulse supply circuit is turned on again to restart and continue electric discharge machining. In this way, we prevent the fire extinguisher from operating easily and spraying extinguishing agent into the EDM machine, which could lead to serious injury. Since the machine stops, the expensive workpiece being machined and the electric discharge machine are prevented from being sprayed with extinguishing agent due to malfunction of the detection element.

Then, due to fluctuations in the internal pressure of the sterilizer, the discharge application II
Turn on and off the power supply at all times to ensure that a fire extinguisher or its extinguishing agent that has not been used for a long time does not deteriorate and become useless in the event of a fire. This also has the effect of inspecting the fire extinguisher.

[Brief explanation of drawings]

The figure is a schematic configuration diagram of the present invention. 1... Fire extinguisher 1a... Pressure switch 2... Pulse circuit switch 3...
...Detector 5...Discrimination circuit 6...When machining voltage pulse supply circuit
Applicant 7-

Claims (1)

[Claims] In an electrical discharge machine equipped with a fire detector for detecting the occurrence of a fire disaster during electrical discharge machining, and a fire extinguisher that is activated by a detection signal from the fire detector, the pressure inside the fire extinguisher is A pressure switch that operates in conjunction with the electric discharge machine, and a circuit that connects the electric discharge machine to a power source that operates the electric discharge machine through the pressure switch, and a fire extinguisher is activated by a detection signal from the fire detector. When the internal pressure of the fire extinguisher fluctuates, the pressure switch opens the circuit connecting the NrA or other electrical discharge machine to stop the operation of the electrical discharge machine, and the internal pressure of the fire extinguisher increases. A fire extinguishing system for an electrical discharge machine, wherein the pressure switch opens to stop operation of the electrical discharge machine when the pressure is not at a predetermined value.